Roll coating is a process of applying a coating to a metal strip whereby, at least in one known process, a first rotating roll is nip fed or partially immersed in coating liquid to receive a layer of coating, the first rotating roll then transferring the coating by contact either directly with the metal strip or with a counter-rotating applicator roll to apply the coating to the metal strip passing between the applicator roll and a back-up roll.
In the roll-coating process, a contact force must be applied between the first roll and the applicator roll, and from applicator roll to strip. It is important to accurately assess the magnitude of these forces. However, in known systems this is difficult because of deflection and resonance of roll support frames and other parts of the roll-coating heads, and because contamination of various moving parts by the coating increases resistance therebetween. It is also difficult to accurately assess the force between various rolls because of backlash and variable frictional resistance between parts of adjusting means.
Furthermore, known roll coating systems are difficult to operate because of an ergonomically poor instrumentation and/or adjustment layout.
Expensive parts must be used in known roll coaters to reduce contamination of sensitive measuring equipment, and because they are under high load and must be miniaturised to fit in small spaces.
The present invention seeks to ameliorate one or more of the abovementioned disadvantages.